1. Technical Field
Embodiments of the invention relate generally to via structures and more particularly, but not exclusively, to fabrication of vias in a printed circuit board.
2. Background Art
Differential signaling by an electronic device is one example of a technique where it is particularly useful to have vias and/or other conductive structures close to one another. In the case of conventional printed circuit board (PCB) manufacturing, holes are drilled in proximity to one another, the holes to later have formed therein respective vias each for propagating through the PCB a different signal of a differential signal pair. The proximity of such vias to one another improves coupling between the signals of the differential signal pair.
However, drilling of such holes is limited by manufacturing tolerances of the fabrication equipment performing the drilling. To avoid the creation of a short between a pair of vias, conventional PCB design must include an offset distance between vias, where the additional distance accommodates a margin of error in the location of one or both holes for such vias. An associated need for impedance control also requires some marginal spacing between vias, in conventional PCB design.
As successive generations of electronic devices continue to exhibit increased functionality such as communication bandwidth, and as these successive generations continue to scale in size, there is expected to be an increasing demand for more compact structures that enable higher-bandwidth signal exchanges. Existing techniques to fabricate vias pose one constraint on how this demand is to be met.